Aquarium cover



FIG. 1 is a front elevational view of an aquarium cover showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a side elevational view thereof; and

FIG. 5 is a perspective view showing the cover in a folded position. 

The ornamental design for an aquarium cover, as shown and described. 